/*
 * Copyright (C) 2015 Square, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package cn.nexd.app.okhttp.android;

import java.io.File;
import java.io.IOException;
import java.net.CacheRequest;
import java.net.CacheResponse;
import java.net.ResponseCache;
import java.net.URI;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;

import cn.nexd.app.okhttp.Cache;
import cn.nexd.app.okhttp.Request;
import cn.nexd.app.okhttp.Response;
import cn.nexd.app.okhttp.android.internal.huc.JavaApiConverter;

/**
 * A class provided for use by Android so that it can continue supporting a {@link ResponseCache}
 * with stats.
 */
public class AndroidShimResponseCache extends ResponseCache {

    private final Cache delegate;

    private AndroidShimResponseCache(Cache delegate) {
        this.delegate = delegate;
    }

    public static AndroidShimResponseCache create(File directory, long maxSize) throws IOException {
        Cache cache = new Cache(directory, maxSize);
        return new AndroidShimResponseCache(cache);
    }

    public boolean isEquivalent(File directory, long maxSize) {
        Cache installedCache = getCache();
        return (installedCache.directory().equals(directory)
                && installedCache.maxSize() == maxSize
                && !installedCache.isClosed());
    }

    public Cache getCache() {
        return delegate;
    }

    @Override
    public CacheResponse get(URI uri, String requestMethod,
                             Map<String, List<String>> requestHeaders) throws IOException {
        Request okRequest = JavaApiConverter.createOkRequest(uri, requestMethod, requestHeaders);
        Response okResponse = delegate.internalCache.get(okRequest);
        if (okResponse == null) {
            return null;
        }
        return JavaApiConverter.createJavaCacheResponse(okResponse);
    }

    @Override
    public CacheRequest put(URI uri, URLConnection urlConnection) throws IOException {
        Response okResponse = JavaApiConverter.createOkResponseForCachePut(uri, urlConnection);
        if (okResponse == null) {
            // The URLConnection is not cacheable or could not be converted. Stop.
            return null;
        }
        cn.nexd.app.okhttp.internal.http.CacheRequest okCacheRequest = delegate.internalCache.put(okResponse);
        if (okCacheRequest == null) {
            return null;
        }
        return JavaApiConverter.createJavaCacheRequest(okCacheRequest);
    }

    /**
     * Returns the number of bytes currently being used to store the values in this cache. This may be
     * greater than the {@link #maxSize} if a background deletion is pending.
     */
    public long size() throws IOException {
        return delegate.size();
    }

    /**
     * Returns the maximum number of bytes that this cache should use to store its data.
     */
    public long maxSize() {
        return delegate.maxSize();
    }

    /**
     * Force buffered operations to the filesystem. This ensures that responses written to the cache
     * will be available the next time the cache is opened, even if this process is killed.
     */
    public void flush() throws IOException {
        delegate.flush();
    }

    /**
     * Returns the number of HTTP requests that required the network to either supply a response or
     * validate a locally cached response.
     */
    public int getNetworkCount() {
        return delegate.networkCount();
    }

    /**
     * Returns the number of HTTP requests whose response was provided by the cache. This may include
     * conditional {@code GET} requests that were validated over the network.
     */
    public int getHitCount() {
        return delegate.hitCount();
    }

    /**
     * Returns the total number of HTTP requests that were made. This includes both client requests
     * and requests that were made on the client's behalf to handle a redirects and retries.
     */
    public int getRequestCount() {
        return delegate.requestCount();
    }

    /**
     * Uninstalls the cache and releases any active resources. Stored contents will remain on the
     * filesystem.
     */
    public void close() throws IOException {
        delegate.close();
    }

    /**
     * Uninstalls the cache and deletes all of its stored contents.
     */
    public void delete() throws IOException {
        delegate.delete();
    }
}
